1. Field of the Invention
The present invention generally relates to separators for electrochemical cells and batteries and more particularly to electrodes which have separators incorporated therein.
2. Prior Art
Certain types of batteries require substantial circulation or irrigation of the electrolyte and in such instances the electrodes must be exposed to the electrolyte while still maintaining their relative positions within the battery. Electrodes have therefore been proposed which have separator particles imbedded in their surfaces but protruding therefrom a sufficient distance to maintain the separation of the electrode from another electrode of opposite polarity. The embedment procedure usually involves having to etch beads of electrically insulative material to cause them to have sufficient mechanical hold to the material lining the cavities in the electrode surface, which cavities have been provided during the embedment. It has been found that such embedment must be to the depth of at least 50% of the bead diameter in order to securely lock the beads in place. In order to assure such deep embedment, the electrode surface must be selected so that it is sufficiently malleable to permit considerable cold flow of material up around the bead without having to apply sufficient embedding force to crush the bead. A second conventional procedure for integrating separator pieces with the surfaces of an electrode involves punching out the separator pieces from a sheet and in the same operation causing them to adhere to the surface of the electrode plate. The equipment needed for such an operation is relatively complicated and sophisticated. Moreover, there are severe limitations on the materials which can be used for separators under such circumstances.
It would be desirable to be able to provide an improved method of integrating separator particles with an electrode surface so as to more rapidly and easily provide the electrode with an integral separator and without previously encountered limitations on the nature of the separator particles and on the nature of the electrode surface. Such method should preferably be inexpensive, utilize conventional materials and provide a durable product.